A conventional pneumatic tire may utilize an outside-in radial ply construction, which aids to torque the tire bead onto the rim of a wheel to which the tire is mounted and allows the rim to provide greater support for the tire. The size of the bead may be reduced, permitting a reduction in the amount of rubber and reinforcement around and above the bead.
A conventional two-ply radial runflat tire may have a belt structure, a ply structure, two inextensible beads, and two wedge-insert reinforced sidewalls. The outer ply may be reinforced by a high-modulus, light-weight aramid. The aramid reinforcement material of the outer ply may be clamped around the beads. The outer ply may be prestressed in tension during manufacture of the tire. The resultant tire may be light in weight and may resist upward buckling of the tread during runflat operation.
Another conventional pneumatic tire may comprise a carcass ply extending between bead portions and a top rubber layer. The top rubber layer may face the inside of the tire and be made of a butyl rubber compound containing at least ten parts by weight of butyl rubber or butyl rubber derivative. This tire may further include a belt disposed radially outside the carcass under the tread portion. The belt may comprise at least one ply of monofilament cords laid at an angle from 10 to 40 degrees with respect to the circumferential direction of the tire with each of the monofilament cords consisting of a single filament. The belt further may comprise one ply of multifilament cords or one ply of monofilament cords. The height of a bead apex, which is disposed between a carcass ply turnup portion and a main portion of the carcass ply at each bead portion, may be reduced to a range from 10 to 20 mm. Thus, the carcass ply turnup portion may extend radially outward beyond the radially outer end of the bead apex so as to adjoin the main portion of the carcass ply.
A conventional radial ply runflat pneumatic tire may have a carcass with a bead portion, a carcass reinforcing structure, and a bead filler. The carcass reinforcing structure may have at least two ply structures with cords extending to each bead. The carcass may include elastomeric first and second fillers. The first filler may be located between the first ply structure and an innerliner of the tire. The second filler may be located between the first and second ply structures. The first and second fillers may stiffen sidewalls of the carcass to permit operation of the tire while uninflated. The tire may further include an aramid overlay radially outward of a belt structure.
Another conventional radial ply pneumatic tire may have a carcass with a first continuous radial ply with shoulder portions and lateral edge portions, a second non-continuous radial ply, and a third non-continuous radial ply. A crown portion of the carcass may have a first edge and a second edge. The second non-continuous radial ply may have a right side extending from approximately the first edge of the carcass crown portion to approximately around a first bead core and a left side extending from approximately the second edge of the carcass crown portion to approximately around a second bead core. The third non-continuous radial ply may have a right side extending from approximately the first edge of the carcass crown portion to approximately around the first bead core and a left side extending from approximately the second edge of the carcass crown portion to approximately around the second bead core. The third radial ply overlays the second radial ply.